JPS5952057B2 - Injection mold changing device for synthetic resin injection molding machine - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a method in which a hydraulically controlled tightening bolt for holding an injection mold on a mold support is movable in a mold clamping direction of a mold clamping unit in a hole in the mold support. It can be pretightened by means of a wedge-shaped sliding member supported and guided at right angles to the tightening direction, which sliding member in the tightening position is pushed through the actuating ramp to the rear of the corresponding ramp of the tightening bolt. a device for linearly moving the injection mold into the operating position, which engages and is respectively connected to the piston of the hydraulic cylinder, is fixed by self-restraint, and also covers the clamping surface of the mold support; The present invention relates to an injection mold changing device for a horizontal mold clamping unit of a synthetic resin injection molding machine.

A known exchange device of this type (German Publication No. 27240
No. 20, “Synthetic resin” (KunststOffe)
70 (1980) 3. pp. 128-131, Ludwig Engel KG,. A43ll Schubert Berg, information paper "Engel-InfOrma"
tiOn) A-67-TV-9/81, etc.), the clamping bolts are strongly connected to the injection mold and extend on both sides of the injection mold in the clamping direction of the clamping unit.

The injection mold is therefore introduced into the clamping space only at a relative distance of the clamping surface of the mold support that corresponds to twice the length of the clamping bolt plus the depth of the injection mold. Therefore, the maximum opening stroke of the mold clamping unit is (taking into account the opening of the mold necessary to release the molded product)
It will be necessary to design a value greater than that required for the maximum depth of the mold. To guide the mold into and out of the working position, not only a linear movement of the clamping unit perpendicular to the clamping direction is required, but also an injection for guiding the clamping bolt into and out of the corresponding hole in the mold support. A further movement of the mold in the clamping direction is also required. A prerequisite for this further movement is that the clamping bolt, which is firmly connected to the mold, is free of this movement.

In the case of the known exchange device mentioned above, this precondition is only met when the sliding member that pretightens the clamping bolt is completely withdrawn from the path of movement of the clamping bolt. For this reason, it is necessary to design the hydraulic cylinder controlling the sliding member with a relatively long hydraulic stroke. Furthermore, the connection between the clamping bolt and the mold is subjected to strong tensile stress during pretightening of the clamping bolt. In order to be able to withstand this tensile stress sufficiently, an important modification of the injection mold aimed at mooring the clamping bolt when fixing it to the injection mold is described in German Published Application No. 2724020. This is necessary even in the simplest case. That is, for each tightening bolt, it is necessary to form a mounting hole for the fixing flange J of the tightening bolt and a large number of threaded holes in the body of the injection mold. As in a similar device according to DE 2332205, the injection mold, which is lowered by a lift device into the clamping chamber of the mold clamping unit, is first fixed on one mold support, and then the other mold support is moved to the mold support. It is also known to run to the injection mold by means of a tightening stroke and then to secure it to the mold support by engaging the mold halves of adjacent molds behind the locking element.

The tilting moment generated when the injection mold descends is
The mold is placed on the clamping surface of one mold support and is supported by the clamping joint of the mold support (No. 7 of the above-mentioned publication).
(See page 1, paragraph 1). In this case, the injection mold is adjusted by means of a yoke which partially grips around the guide beam of the movable mold support. In this case, the addition of a yoke to the injection mold requires a major modification of the injection mold, which is usually standardized, and requires the use of various yokes of different sizes for injection molds of various sizes. arise.

Also, these yokes cannot eliminate the tilting moment of an injection mold regularly suspended on a lifting device in a tilted position. To eliminate this tilting moment, in order to seat the injection mold properly on the clamping surface of the adjacent mold support before securing it to the mold support with a clamping joint,
It will probably be necessary to move the descending injection mold even slightly in the mold clamping direction. Furthermore, standardized injection molds (Susta
n), 6 Frankfurt Main, Catalog K4OO
- European Series, "Forming Tool Standards", EO-Kummerner KG, 588 Reudenshaide, EOC Standards, and U.S. Pat. It is also known to tighten.

In this case the pawl engages the rear part of the caul plate. The hydraulic drive device required for this purpose is relatively expensive because it has a structure in which the tightening bolt is first rotated and then tightened in the axial direction. Tighten! It is not possible to fix the bolt in the tightened position independently of the hydraulic system, i.e. on a self-restrictive basis, since this requires a rotational movement. Therefore, if the hydraulic system fails, the injection mold may loosen from its tightened position (
Hemheld (P1'6mhe1d) 1 company, 6312 Laubacha "Rotating fastener" contents manual). Taking into account the above-mentioned known technology, the present invention improves the above-mentioned type of exchange device, simplifies the structure, eliminates the need for major changes to standardized injection molds, and improves automation and standardization. The purpose is to make it easier to handle under specified conditions.

This problem is achieved according to the invention by the features indicated in the characterizing part of claim 1.

According to this configuration, the horizontal transport path of the injection mold is guided between the two mold supports without any tilting moment and with a minimum play, and can be fixedly clamped to both mold supports. This results in a straight path orthogonal to the mold clamping direction of the unit.

The device can also be replaced with commercially available standardized injection molds without any or particularly major changes.
In contrast to the sliding member according to the prior art, which requires the sliding member to be completely pulled out from the tightening bolt that is strongly connected to the injection mold when replacing the mold, according to the present invention, these members are constantly engaged. Because of this, the operating process simply involves overcoming the guiding gap between the clamping surface of the clamping bolt and the bearing surface of the mold.

This allows the use of very short length hydraulic cylinders to control the sliding members, which are placed on the sides of the mold support to define the maximum width of the injection molding machine. It has a particularly important meaning in this case. According to the solution of the invention, the inclined working surface of the sliding member is such that the working surface of the sliding member is subjected to a tensile force when moving the tightening bolt into the tightening position (claim 3). For the first time, the prerequisite of tilting with respect to the direction of movement of is fulfilled.

A greater hydraulic pressure of the hydraulic cylinder is therefore advantageously available in order to release the self-locking of the sliding member, which is particularly significant in the case of changing devices of the type mentioned at the outset. Other features of the invention are set out in the following claims.

Next, the embodiment shown in the drawings will be described in further detail.

The machine stand 10 has a rail or rail 11, and the rail 11 covered with an angle member 11a is fixed to a flange 0a of the wall of the machine stand 10.

A mold clamping unit of an injection molding machine is mounted on the rail 11. The mold clamping unit includes a fixed mold support 13, a support plate (not shown) for a hydraulic drive, and beams 46, 47. These girders are fixed mold supports 13
and is accepted by the support plate. A movable mold support 14 is movably supported on the girders 46 and 47, and the mold support 14 is formed in a box shape and includes a clamping plate 14a, a pressure receiving plate 14b, and a pressure transmitting rib 14C. We are prepared. The mold support 14 is supported on the rail 11 via a support member 19. The operating slope 51 of the sliding member 28 is always in contact with the slope 48 of the tightening bolt 20.

The relative movement of the tightening bolt 20 and the sliding member 28 generates an axial movement component of the tightening bolt 20, which is used to tighten or loosen the mold 17. A prerequisite for this operation is a highly linear movement of the sliding member 28 perpendicular to the axis of the clamping bolt 20, which movement is, when pretightening the clamping bolt 20,
The size is on the order of about 1-3 mm. The mold 17 is simultaneously supported on both mold supports 13, 14 and guided horizontally.

The mold 17 can be pushed straight into the clamping position via a guide rim 18 extending parallel to its parting plane b--b. The guide rim 18 is fixed to the clamping surface of the associated mold support 13, 14 via a fixing screw 38 and is aligned with the mold support by means of a centering pin 39. When the mold] 7 is pushed into the clamping position, it is guided along the clamping surfaces of the hand mold supports 13, 14 and the guide edge material 18 by the longitudinal sliding surface 45 of the backing plate 17a. The gripping end 20b of the tightening bolt 20 integrally transitions into the tightening bolt 20 via a piece 20a having an anti-circular cross section. Guide pins 18b are arranged on the outside of the beams 46, 47 in order to basically prevent the beams 46, 47 from being damaged when the mold 17 is pushed into the clamping position.

The guide surfaces of these guide pins are within the sliding surfaces 45a of the adjacent guide edge members 18. A fixed mold support 13 with a reinforcing plate 13b is centered on the rail 11 via a support rib 13a. The girder 46 is used for the mold support 13 and the movable mold support 1
Together with support plates (not shown) for the four hydraulic drive cylinders, the member 25 for fixing the spar material forms one rigid frame. The slope 48 of the tightening bolt 20, which corresponds to the operating slope 51 of the sliding member 28, forms an angle of 6 to 7 degrees with respect to the axis of the tightening bolt 20.

This slight angle ensures that the associated sliding member 28 is self-locking in the clamped position. Two adjacent sliding members 28 can be connected to each other via coupling elements in the same tightening direction and can be controlled by a single hydraulic cylinder.

The sliding member 28 is arranged inside the mold support 13 or 14 and guided therein. Each sliding member 28 grips the associated tightening bolt 20 in the slot 12. The associated sliding member 28 always rests with its operating slope 51 against the slope 48 of the tightening bolt 20. The hydraulic cylinder 23 driving the sliding member 28 is fixed to the side edge 67 of the mold support 13 or 14 by means of a fixing screw 36. The sliding member 28 generates a tensile force on the tightening bolt 20 and receives a tensile force itself when it moves to the tightened position, and receives a compressive force when the injection mold is loosened to escape the self-restriction. Each mold support 13, 14
A tightening bolt 20 is axially movably supported in the through hole of the
can be moved to the tightening position against the action of the coil spring 61. The coil spring 61 is disposed in blind holes 62 of the tightening bolt 20, and these blind holes 62 are disposed on the mold 17 side of the slit 12. Each tightening bolt 20 is provided with a lubricating device 74 on the opposite side of the slit 12. The lubrication device 74- has a lubrication path 66 coaxial with the coil spring 61, and the lubrication path 66 is connected to the slopes 48, 5.
It terminates at 1. The tightening bolt 20 is attached to the mold support 13,
Beyond the plane x-x of the clamping surface of 14, the injection mold 17
extending toward the separation plane bb.

Most of the cross-sectional area Q (FIG. 3) of the tightening bolt 20 lies outside the plane of the mold support 13 covered by the backing plate 17a of the mold half 17h. The backing plates 17a abut on the guide edges 18 of the mold supports 13, 14 on opposite sides of the mold 17, and the tightening bolts 20 grip the rear of the bearing surfaces 44. The gripping end 20b may be formed by a threaded nut (not shown) that engages with the external thread of the tightening bolt 20. The parallel projection cross-sectional areas Q and P of the tightening bolt 20 and the mold 17 in the mold clamping direction overlap each other. Mold support 13,1
The sliding member 28, whose free end is guided on the inner bearing surface 0 of the die carrier 4, is guided into the guide bush 54, which is fitted into the bore 73 of the mold supports 13, 14.

The cup-shaped cylinder member 23b is formed by mold supports 13,1.
It is spaced apart from the side edge 67 of the guide bushing 54 and is fitted concentrically into the annular waste portion 69 of the guide bushing 54. The sliding member 28 is located in the clamping plate '14a of the mold support 14 or in the central plane mm of the mold support 14. The coil spring 61 is supported by the adjacent sliding member 28 via a spacer pin 63. The backing plate 17a of the mold 17 projects into the notch 70 of the tightening bolt 20. The notch 70 corresponds to the support surface 44 of the backing plate 17a.
It is delimited on one side by a clamping surface 64 perpendicular to the direction of movement R of the sliding member 28 and on the opposite side by a wall 65 which includes an angle of approximately 45° with the direction of movement R. The clamping bolt 20 disposed in the clamping plate 14a of the mold support 14 completely or almost completely passes through the clamping plate 14a by means of a through hole 40. The tightening bolts 20 arranged in the mold support 13, as well as the holes in which they are accommodated, terminate in the hollow chamber 71 of the mold 13. The sliding member 28 is directly connected to the associated piston 31 and, to that extent, also assumes the function of a piston rod. The stroke length e of each hydraulic cylinder 23 corresponds to approximately 1/3 of the diameter of the tightening bolt 20, and the tightening surface 64 of the tightening bolt 20, which has not been tightened beforehand, and the bearing surface 44 of the mold
is slightly larger than the distance between The base end wall 20e of the tightening bolt 20 is located at a distance y (see FIG. 4) from the sliding surface 45, which is the gripping surface or longitudinal edge surface of the adjacent backing plate 17a (mooring plate). As can be seen in particular from FIGS. 2 and 3, the mold supports 13, 14 have additional screws for receiving and fixing fixing screws 38, centering pins 39 and tightening bolts 20 for the guide edge 18. Alternative holes 40, 39a, 38a are provided on different sides of the mold supports 13, 14 for guiding edges 18 and tightening bolts 2.
It is arranged so that it is possible to selectively arrange 0's.

Therefore, when changing the mold, it is possible to select either the horizontal pushing direction H or the vertical pushing direction for the mold 17. In this case, the push-in movement in each case is such that when the tightening position is reached, the stop element 1
8a. The box-shaped movable mold support 14 is driven by a hydraulic drive via a piston rod 15 and a pressure plate 16.

[Brief explanation of the drawing]

1 is a schematic sectional view of the fixing device with the mold support partially shown; FIG. 2 is a sectional view taken along the line 11--11 of FIG. 1; and FIG. 3 is a fixing consisting of only two tightening bolts. FIG. 4 is an enlarged sectional view of a part of the fixing device of FIG. 1; FIG. Explanation of symbols, 13, 14... Mold support, 17.
... Injection mold (half mold), 18 ... Guide edge material (guide element), 20 ... Tightening bolt, 2
0a...Gripping end, 20b...Gripping tip, 28...Sliding member, 45...Sliding surface, Q, P... - Cross-sectional area (surface).

Claims (1)

[Scope of Claims] 1. An injection mold changing device of a horizontal mold clamping unit of a synthetic resin injection molding machine, which comprises a hydraulically controlled clamping bolt for holding the injection mold on a mold support. The clamping can be performed in advance through a wedge-shaped sliding member that is supported movably in the mold clamping direction of the mold clamping unit in the hole of the mold support and guided at right angles to the clamping direction, and the sliding member is In the tightening position, the clamping bolts engage the rear part of the corresponding ramp of the tightening bolt through the actuating ramp, are each connected to a piston of the hydraulic cylinder and are fixed by self-restraint, and in addition:
Injection molding that is simultaneously supported and guided by both mold supports 13, 14, in which a device is provided for linearly moving the injection mold, which covers the clamping surface of the mold support, into and out of the working position. The mold 17 is engaged with the rear of the bearing surface 44 even when the clamping bolts 20 of both mold supports are not in the operating position, and the operating slope 51 of the sliding member 28 is always engaged with the rear of the slope 48 of the clamping bolt 20. An exchange device characterized by a combination of: 2. The support surface 44 extending perpendicularly to the mold clamping direction of the mold clamping unit and extending over the entire injection mold 17 is formed by the patch plate 17a of the injection mold 17 that is moved horizontally, and the patch plate 17a The changing device according to claim 1, characterized in that the changing device projects beyond the other plate of the injection mold 17. 3 Move the inclined operating slope 51 of the sliding member 28 in the movement direction R.
so that a tensile force is generated in the tightening bolt 20 when the tightening bolt 20 is moved to the tightening position,
In this case, the free end of the actuating ramp 51 is aligned with the associated mold support 1
3 and 14, respectively (FIG. 4).
Replacement device as described in section. 4 The tightening bolts 20 that cannot be tightened in advance are also
1, the operating slope 51 of the associated sliding member 28
Claim 1 characterized in that the device is always in contact with the
The exchange device according to item 1 of 3. 5. The fourth aspect of the present invention is characterized in that a spring 61 formed as a coil spring is arranged in the center hole 62 of each tightening bolt 20, and is supported against the adjacent sliding member 28 by a spacer pin 63. Replacement device as described in section. 6. A lubricating device 74 equipped with a lubricating passage 66 is installed in each tightening bolt 20, and the lubricating passage 66 is arranged coaxially with respect to the coil spring 61 and terminates at the operating slope 51 of the sliding member 28. An exchange device according to claim 5, characterized in that: 7 Tighten the stroke length e of the hydraulic cylinder 23 with the bolt 20
, and is slightly larger than the distance between the clamping surface 64 of the clamping bolt 20 that is not pre-tightened and the bearing surface 44 to which the injection mold 17 belongs. Exchange device according to one of the ranges 1 to 6.